Heat exchanger

ABSTRACT

A tube and shell heat exchanger is provided with indexing or orienting means for properly arranging the tube bundle relative to the inlet and outlet means for fluid flowing around the tubes and with baffles in the same plane as the tubes in the areas of the inlet and outlet means for elimination of dead space in these areas.

United States Patent 1191 Smith Apr. 23, 1974 1 HEAT EXCHANGER 1,810,286 6/1931 MacPhee 165/158 [75] Inventor: ose E. s th, aytown Te 1,726,943 9/1929 Bergqulst e! a] 165/158 [73] Assignee: Essa Reseaichsmd gnjgineering Primary Examiner chafles l Myhre ompany m Assistant Examiner--Theophil W. Streule, Jr. [22] Filed: Oct. 20, 1972 [2]] App]. No.2 299,559 57 ABSTRACT [52] U S Cl 165/76 165/161 A tube and shell heat exchanger is provided with in- [51] F128) 7/00 dexing or orienting means for properly arranging the [58] Fieid M 58462 tube bundle relative to the inlet and outlet means for "165/76 78 6 fluid flowing around the tubes and with baffles in the same plane as the tubes in the areas of the inlet and 56] References Cited outlet means for elimination of dead space in these ar- UNlTED STATES PATENTS 2,269,619 1/1042 Carpenter 165/161 3 Claims, 5 Drawing Figures RMENTEU APR 2 3 197 TUBE BUNDLE l3 DEA D SPACE 24 DEAD SPACE 8 1 m\l\ 2 G V F I. M d 3% 1 2 9 9 2 2 JWELD FIG. 5.

HEAT EXCHANGER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a tube and shell heat exchanger. More particularly, the invention is concerned with proper installation of tube bundles and elimination of dead space in areas adjacent the inlet and outlet means for fluid flowing around the tubes. In its more specific aspects, theinvention is concerned with an orientation or indexing means for tube bundles and means for eliminating dead spaces in tube bundles of heat exchangers.

2. Description of the Prior Art It has been recognized heretofore that problems exist in insuring proper orientation of tube bundles in tube and shell heat exchangers. Means such as dowel pins, marking the bundles on top, and the like have been attempted, but heretofore no one has provided a positive means for orientation of tube bundles in heat exchangers. Devices for positively insuring proper orientation of bundles within shells are not provided on heat exchangers, and there are no such positive effective devices known. Numerous instances have been noted where incorrectly installed tube bundles have resulted in very poor heat transfer, accelerated corrosion, extra maintenance, or extreme vibration resulting in tube failure. In one instance an important processing unit has even been forced to shut down because of broken tubes resulting from incorrect bundle installation. The insidious feature of this problem is that its results are not readily noticeable but have to be diligently sought out. As a result, once a bundle is installed incorrectly no one realizes that sizable losses are occurring. Incorrectly installed bundles in the one processing unit area alone produced excessive maintenance costs.

Another facet of this problem is that quite often bundles are installed with the tube sheet center line a few degrees out of plumb, and the channel baffles ride up on the tube sheet. This results in part of the tube fluid bypassing the exchanger and in deformation and subse quent repairs to both baffle and tube sheet. No attempt is made to evaluate these losses, but an accurate and positive orientation device in accordance with the present invention eliminates them.

Moreover, in the manufacture of tube and shell heat exchangers, space and economic limitations decree that end cross baffles be spaced about two feet from the tube sheets. Also, in most instances tube support plates" are installed on the floating end of the bundle to support the overhanging floating tube sheet/head arrangement. These features result in a large area of re-- duced shell velocity at both the inlet and outlet-ends of the bundles, with a resulting built-in dead space between the tube support plate and floating head. Corrosion rates within those areas are nearly alwaysat least double thosein'other areas of thebundle. t

The following listed U.S.-Pats. were considered in s ru sfiq ith.- l ..,i P n N 41 .1 7 2,577,832 3,315,738; 3,351,131; 3,376,028; 3,580,225.

SUMMARY OF THE INVENTION The present invention may be briefly described and summarized as involving a shell and tube heat exchanger wherein positive orientation means is provided for the tube bundle relative to the inlet and outlet means for fluid flowing around the tubes and means for eliminating dead spaces in the areas of said inlet and outlet means.

BRIEF DESCRIPTION OF THE DRAWING eliminated;

FIG. 3 illustrates in partial section the heat exchanger of FIG. 2 with a positive orienting device;

FIG. 4 is a sectional view taken along the lines 4-4 of FIG. 3; and

FIG. 5 is a partial sectional view taken along the lines 55 of FIG. 4.

DESCRIPTION OF THE PREFERRED MODE AND.

EMBODIMENTS RELATIVE TO THE DRAWING Referring now to the'drawing and particularly to FIG. 1, numeral 11 designates the shell of a heat exchanger having an inlet 12 for flow of heat exchange fluid around the tubes of tube bundle 13 and baffles 14 to outlet 15. The tube sheet 16 is connected between flanges 17 and 18 to heat exchanger head 19 having an inlet 20 and outlet 21 and is provided with baffles or means 22for directing the fluid to be heated into the tubes (not shown) of tube bundle 13. Heat exchanger 11 has a floating end support ring 23 and it will be apparent that dead spaces 24,25, and 26 exist. These dead spaces 24, 25, and 26 reduce heat transfer, reduce velocity, allow solids to collect, alter temperature profiles and also increase corrosion rates.

In FIG. 2, the dead spaces are eliminated by eliminating the ring 23 and providing baffles 28 and 29. It will be noted that the baffles 28 are supported by the tube sheet 16 and the first baffle 14 and the baffles 29 are supported by the last baffle 14 and floating end 27.

The space 24a inside the closure means 24b is unimportant and poses .no problems since the fluid in it does not affect the tube bundle 13.

In order to install the tube bundle l3 properly, referring now to FIG. 35, the tube sheet 16 is provided with a longitudinal member 30 which may be a rod or protu berance, and flange 17 is provided with an opening or hole 31. It is understood, of course, that other orienting or indexing means may be used and that the protuberance and its receiving means may be reversed, that is,

the rod may be on the flange and the receiving means on the tube sheet. I

If a tube bundle is installed upside'down, the problems are magnified since most tubebundles are provided with an impingement plate to-protect the'tubes at entry of the fluid flowing aroundjthem. In such a case, there is no protection. Likewise, the longer tube span at inlet and outlet allows excessive vibration and may lead to tube breakage with the bad consequences thereof. Furthermore, such incorrect installation leads to long totally dead spaces at the inlet and outlets which reduces heat transfer by at least 25 percent in an average l6-foot-long unit,and corrosion rates are increased tremendously in the affected areas.

Thus, it will be clear that the present invention allows the obtaining of new and unobvious advantages and results and is quite useful and therefore patentable.

The nature and objects of the present invention having been clearly described and illustrated and the best mode and embodiment contemplated set forth.

What I wish to claim as new and useful and secure by Letters Patent is:

1. In a tube and shell heat exchanger including a bundle of tubes through which a first fluid may be passed, a tube sheet from which said bundle of tubes extends, and an outer shell which surrounds said bundle of tubes and tube sheet, said outer shell containing an inlet and an outlet for the contacting of a second fluid with said tubes in indirect heat exchange with said first fluid, the improvement which comprises first orienting means associated with said bundle of tubes and said tube sheet and second orienting means associated with said outer shell, said first orienting means engaging said second orienting means when said bundle of tubes and tube sheet are properly positioned angularly with respect to said outer shell.

2. A heat exchanger as defined by claim 1 wherein one of said orienting means comprises a protruding member and the other of'said orienting means comprises an opening into which said protruding member extends when said bundle of tubes and tube sheet are properly positioned angularly with respect to said outer shell.

3. A heat exchanger as defined by claim 1 wherein said first orienting means comprises a rod affixed to said tube sheet and said second orienting means comprises an opening in a flange on said shell into which said rod extends when said bundle of tubes and said tube sheet are properly positioned angularly with respect to said shell. 

1. In a tube and shell heat exchanger including a bundle of tubes through which a first fluid may be passed, a tube sheet from which said bundle of tubes extends, and an outer shell which surrounds said bundle of tubes and tube sheet, said outer shell containing an inlet and an outlet for the contacting of a second fluiD with said tubes in indirect heat exchange with said first fluid, the improvement which comprises first orienting means associated with said bundle of tubes and said tube sheet and second orienting means associated with said outer shell, said first orienting means engaging said second orienting means when said bundle of tubes and tube sheet are properly positioned angularly with respect to said outer shell.
 2. A heat exchanger as defined by claim 1 wherein one of said orienting means comprises a protruding member and the other of said orienting means comprises an opening into which said protruding member extends when said bundle of tubes and tube sheet are properly positioned angularly with respect to said outer shell.
 3. A heat exchanger as defined by claim 1 wherein said first orienting means comprises a rod affixed to said tube sheet and said second orienting means comprises an opening in a flange on said shell into which said rod extends when said bundle of tubes and said tube sheet are properly positioned angularly with respect to said shell. 